1 files changed, 1 insertions, 1 deletions
diff --git a/diff.h b/diff.h
index 5be1ee77a7..d75e6d15e2 100644
--- a/diff.h
+++ b/diff.h
@@ -354,7 +354,7 @@ extern const char *diff_aligned_abbrev(const struct object_id *sha1, int);
 extern int run_diff_files(struct rev_info *revs, unsigned int option);
 extern int run_diff_index(struct rev_info *revs, int cached);
 
-extern int do_diff_cache(const unsigned char *, struct diff_options *);
+extern int do_diff_cache(const struct object_id *, struct diff_options *);
 extern int diff_flush_patch_id(struct diff_options *, unsigned char *, int);
 
 extern int diff_result_code(struct diff_options *, int);